36.5. The Minister may reduce that part of the amount of real estate taxes attributable to land and qualified for reimbursement by a percentage equivalent to the unproductive area of the agricultural operation situated in the agricultural zone, where the unproductive area, on any date from 1 July to 1 October of the calendar year ending before the beginning of the fiscal year for which an application for reimbursement is made, represents more than 25 % of the total area of the agricultural operation situated in the agricultural zone, except where it is proved to the Minister that the part of the total area in excess of 25 % was productive at another period in the year, or where it is proved to the Minister that the part of the total area in excess of 25 % cannot be improved.